RefDoc
Haut

Faire une nouvelle recherche
Make a new search
Lancer la recherche


Titre du document / Document title

Colonial breeding and nest defence in Montagu's harrier (Circus pygargus)

Auteur(s) / Author(s)

ARROYO Beatriz (1) ; MOUGEOT Francois (1) ; BRETAGNOLLE Vincent (1) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) CNRS/CEBC, 79360 Villiers en Bois, FRANCE

Résumé / Abstract

We assessed whether colonial breeding allows individuals to decrease their investment in predator defence, by presenting decoys of owls, foxes and crows to Montagu's harrier, Circus pygargus. Decoy detection increased with colony size, as did the number of individuals mobbing the decoy. The number of mobbers was greater for predators potentially risky for the adults (owl or fox) than for non-dangerous predators (crow). Recruits (breeding neighbours, fledglings and non-breeders) were present a lower percentage of the time, and attacked and alarm called less frequently than tested individuals. Nevertheless, the overall attack rate on the predator increased with the number of mobbers. When the size of the mobbing group increased, individuals were more likely to attack predators that represented a risk for adults, but did so less intensively and with a lower frequency of close dives. Thus, coloniality decreased the individual costs of defence in terms of risk taken, whilst enhancing defence efficacy. Birds alarm called more intensively when presented with dangerous predators than with the crow. The number of recruits significantly increased with increasing alarm rate of the tested individuals, even when taking colony size into account. Furthermore, the alarm rate of the tested birds also had a significant effect on the proportion of recruits that engaged in attacks against dangerous predators but not against the crow. The higher recruitment and attack rates for dangerous predators were thus apparently modulated through alarm calling. We discuss whether tested birds may manipulate recruits' behaviour to lessen their own risk.

Revue / Journal Title

Behavioral ecology and sociobiology    ISSN  0340-5443   CODEN BESOD6 

Source / Source

2001, vol. 50, no2, pp. 109-115 (53 ref.)

Langue / Language

Anglais

Editeur / Publisher

Springer, Berlin, ALLEMAGNE  (1976) (Revue)

Mots-clés anglais / English Keywords

Vertebrata

;

Aves

;

Animal communication

;

Social interaction

;

Risk

;

Europe

;

Field study

;

Predation

;

Time budget

;

Group size

;

Alarm

;

Sound production

;

Antipredator behavior

;

Intraspecific relation

;

Breeding behavior

;

Mots-clés français / French Keywords

Vertebrata

;

Aves

;

Communication animale

;

Interaction sociale

;

Accipitridae

;

Circus pygargus

;

Risque

;

Europe

;

Etude sur terrain

;

Prédation

;

Budget temps

;

Dimension groupe

;

Alarme

;

Emission sonore

;

Comportement antiprédateur

;

Relation intraspécifique

;

Comportement reproducteur

;

Mots-clés espagnols / Spanish Keywords

Vertebrata

;

Aves

;

Comunicación animal

;

Interacción social

;

Riesgo

;

Europa

;

Estudio en campo

;

Rapiña

;

Presupuesto tiempo

;

Dimensión grupo

;

Alarma

;

Emisión sonora

;

Conducta antidepredador

;

Relación intraespecífica

;

Conducta reproductora

;

Localisation / Location

INIST-CNRS, Cote INIST : 15911, 35400009848657.0020

Nº notice refdoc (ud4) : 14099006



Faire une nouvelle recherche
Make a new search
Lancer la recherche
Bas